A Text Book on Engineering Graphics - Central Board of Secondary ...

ISOMETRIC PROJECTION
Steps:
Exmple : 1.27
1. Draw an isometric projection of the box that encloses a pentagonal prism having
one rectangular face perpendicular to V.P.
2. Indicate the centre of the top pentagonal face with conventional lines.
3. Around the centre 'O' draw a rhombus for the circular base of cone. Using four
centre method draw an ellipse inside. Draw the axis of the cone from the centre
of base to apex.
4. Join all the visible edges (no hidden lines) of the two solids by using thick lines.
5. Complete the isometric projection of the two solids with dimensioning, direction
of viewing and their common axis using conventional lines.
Draw an Isometric Projection of hemisphere resting centrally on its curved
surface, on the top horizontal rectangular face of an equilateral triangular prism,
keeping two triangular faces parallel to the V.P. Side of equilateral triangle = 50
mm, length of the prism = 70 mm and diameter of the hemisphere = 60 mm.
HELPING FIGURE
50
O
ENGINEERING GRAPHICS
70 o
30
Fig 1.34
01
ISO 30
O
Ø60
50
ISOMETRIC PROJECTION
30
o
F
31